1. Field of the Invention
This invention relates to power tools, and more particularly concerns a hand-held power saw employing a continuous abrasive wire rope cutting element.
2. Description of the Prior Art
Numerous abrasive wire or cord cutting devices have been disclosed in the prior art. Various abrasive wire saws have been employed in the cutting of concrete, stone, steel and other materials. For example, U.S. Pat. No. 4,907,564 to Sowa, et al., discloses a wire rope surrounded by a plurality of abrasive sleeves which are spaced apart at predetermined intervals longitudinally of the wire rope. In the form of a closed loop, the wire rope is advanced around rollers while urged against a workpiece.
U.S. Pat. No. 4,766,875 to Feigelson discloses a device employing an endless wire which carries a slurried abrasive cutting material such as silicon carbide particles. The device is designed to deposit and recover the cutting particles and recirculate them for use upon the wire. This is a large and complex apparatus which relies upon pressure exerted upon the wire by weights to achieve a cutting effect.
U.S. Pat. No. 4,832,411 to Johnston, et al., relates to a method of cutting an interior surface in reinforced concrete. In this process, holes are drilled to define the shape of concrete to be removed. Slots are then cut between the holes using an endless wire saw. The wire saw is secured in the cutting operation at the interior end of the holes by swivel pulleys secured at the exterior end of the holes to the concrete surface. Apparatus which drives the saw is complex and requires an elaborate set up process as well as drilling equipment.
Other wire rope cutting saw devices are disclosed in U.S. Pat. Nos. 4,903,682 to Kurokawa, 4,893,607 to Kubo, and 4,484,502 to Abner. These devices, although well adapted to the intended purpose of cutting large blocks of stone, concrete or similar materials, suffer from the common limitations imposed by the size and complexity of the apparatus. The Kubo and Kurokawa devices utilize an endless wire loop secondary rotating circuit cutting means driven by a primary rotating circuit loop. The complexity of the drive systems preclude their use in small hand-held cutting implements. The Abner device discloses a system in which a non-continuous segment of abrasively coated wire rope is reciprocally drawn between two rotating motorized drums. This device also is not amenable to use in a hand-held cutting implement.
It is therefore an object of the present invention to provide a continuous endless abrasive wire rope cutting device amenable to use in hand-held implementation.
It is another object of the present invention to provide a device of the aforesaid nature which is compact, light-weight and simple in construction.
Further objects of this invention are to provide a device of the aforesaid nature which is durable, safe, and amenable to low cost manufacture.
These and other beneficial objects and advantages will be apparent from the following description.